A Walk past the MOST POWERFUL Diesel Loco EVER built, EMD DDAX40 then owned by Union Pacific Railroad and numbered #6930.
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In this Video, I walked past this Giant, at normal speed and it took 30 seconds to cross it with the Mobile Video on hand. The DDA40X is 98 ft (30 m) long.
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Brief...
more...

of loco:
This loco of the class of DDA40X was Made by General Motors EMD division, is a 6,600 hp (4.92 MW) D-D diesel-electric locomotive.
The DDA40X uses two diesel engines (each 3,300 hp (2.46 MW)) and is the most powerful single-unit diesel locomotive ever built in the whole world.
It is nicknamed "Centennial" and "Big Jack". 'X' in the code stands for eXperimental.
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Forty seven units were built between June 1969 and September 1971, except the first one delivered in April in time to participate in the celebrations of the centennial anniversary of the completion of the Transcontinental Railroad driving the "Gold Spike Limited" and arriving in Salt Lake City, Utah, on the morning of May 10, 1969. The units were numbered from 6900 to 6946, with 6936 still in service.
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By 1974, averaging 22,000 miles a month, most DDA40X units had run over 1,000,000 miles and needed more maintenance.[3] Union Pacific began retiring its DD40Xs in 1984 due to rising maintenance costs, with all retired by the end of 1986. However #6936 is still in service with UP, though mostly in excursion service.
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Loco #6936 is the sole example of the "Centennial" type that is still in operation, and thus is the largest operational diesel-electric locomotive in the world. It is occasionally used on both excursion trains and in revenue freight service.
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Owners of the content:
Video & Pic 1: Captured by myself (Sudarshan) inside the loco display shed at Illinois Railway Museum on 5th Oct 2014.
Pic2: Only for reference purposes downloaded from click here and edited, where as the actual owner of the photograph is Bill Grenchik, who captured it on 2 SEP 2008 at the same location outside the shed.
Note:----> Much of the above published information is copied and collated from Wikipedia...